JP7537177B2 - Electro-optical device and electronic device - Google Patents

Description

The present invention relates to an electro-optical device and an electronic device.

One example of an electro-optical device is an active drive type liquid crystal device with switching elements in the pixels. Such liquid crystal devices are used, for example, as light valves in projectors as electronic devices.

The liquid crystal device has a liquid crystal panel with a display area in which multiple pixels are arranged. A flexible printed circuit (FPC) is connected to the terminals of the liquid crystal panel via an anisotropic conductive film (ACF). Drive signals, drive voltages, and video signals are supplied from a higher-level circuit to the liquid crystal panel via the flexible printed circuit.

In recent years, with the miniaturization and high definition of liquid crystal devices and other electronic devices, the wiring pitch of wiring boards and the electrode terminals of electronic components are becoming finer, and anisotropic conductive films that can accommodate fine pitches are also required. However, if conductive particles are densely packed in an anisotropic conductive film to ensure that conductive particles are sandwiched between narrowed electrode terminals and electrical conduction is ensured, the occurrence rate of short circuits between terminals due to the conductive particles dispersed between electrode terminals becoming continuous increases. Therefore, anisotropic conductive films that can prevent short circuits between terminals due to conductive particles being connected in the space between the terminals of fine-pitched connection electrodes are being developed. For example, Patent Document 1 discloses an anisotropic conductive film (hereinafter referred to as a particle-aligned anisotropic conductive film) in which conductive particles are regularly arranged in a predetermined arrangement pattern as an anisotropic conductive film that can accommodate fine pitches.

JP 2020-38993 A

However, when reducing the panel size without changing the resolution of the liquid crystal panel, or when increasing the resolution without changing the panel size, it becomes necessary to optimize the width, length, and other dimensions of the connection terminals with an external wiring board such as a flexible wiring board, as well as the terminal pitch, to match the narrowing of the terminal area caused by the reduction in panel size and the increased number of terminals caused by the increase in resolution.
In such cases, the particle-aligned anisotropic conductive film used must be changed to one appropriate for the size and arrangement pitch of the connection terminals of the liquid crystal panel. However, for manufacturers who produce liquid crystal panels with many different panel sizes and resolutions, preparing many different types of particle-aligned anisotropic conductive films to match the various types of liquid crystal panels increases the cost burden. Therefore, there is a demand to standardize particle-aligned anisotropic conductive films as much as possible for different types of liquid crystal panels.
If a particle-aligned anisotropic conductive film that matches the size and terminal pitch of the connection terminals of the liquid crystal panel cannot be used, the number of conductive particles 71 held in the terminals will be drastically reduced or variations will occur between each terminal, resulting in poor connection between the liquid crystal panel and the flexible wiring board.

The electro-optical device comprises an electro-optical panel and a wiring board electrically connected to a terminal portion of the electro-optical panel by conductive particles arranged in an aligned state in a planar view, the terminal portion having a plurality of terminals arranged in a first direction along one side of the electro-optical panel, the terminals having long sides along a second direction that intersects obliquely with the first direction and short sides along a direction that intersects with the second direction, and the conductive particles are arranged in a third direction that intersects with the second direction.

The electronic device includes the electro-optical device described above.

FIG. 1 is a perspective view showing a configuration of a liquid crystal device. FIG. 2 is a side view illustrating the configuration of the liquid crystal device illustrated in FIG. FIG. 2 is a plan view showing a configuration of a terminal portion of the liquid crystal device according to the first embodiment. FIG. 2 is a plan view showing a configuration of a terminal portion of a liquid crystal panel. FIG. 2 is a plan view showing a configuration of an external terminal of a wiring board. FIG. 1 is a plan view showing a configuration of a particle-ordered anisotropic conductive film. FIG. 1 is a plan view showing a state in which a liquid crystal panel and a wiring board are connected via a particle-aligned anisotropic conductive film. FIG. 1 is a schematic diagram showing a configuration of a projector as an electronic device. FIG. 11 is a plan view showing a configuration of a terminal portion of a liquid crystal panel according to a second embodiment. 10 is a cross-sectional view taken along line A-A' of the terminal portion shown in FIG. 9 . FIG. 11 is a plan view showing a configuration of a terminal portion of a liquid crystal panel according to a first modified example. FIG. 11 is a plan view showing a configuration of a terminal portion of a liquid crystal panel according to Modification 2. FIG. 11 is a plan view showing a configuration of a terminal portion of a liquid crystal panel according to Modification 3. FIG. 13 is a plan view showing a configuration of a terminal portion of a liquid crystal panel according to Modification 4. FIG. 13 is a plan view showing a configuration of a terminal portion of a liquid crystal panel according to Modification 5. A cross-sectional view along line B-B' of the terminal portion shown in Figure 7. A cross-sectional view along line C-C' of the terminal portion shown in Figure 7.

1 and 2, a liquid crystal device 500 serving as an electro-optical device includes a liquid crystal panel 100 serving as an electro-optical panel, and a wiring board 110 connected to one side of the liquid crystal panel 100. Note that Fig. 1 and Fig. 2 are omitted as appropriate to the extent that they do not interfere with the description of the configuration, operation, and effect of the present invention. The liquid crystal device 500 is used, for example, as a light valve of a projector 1000 serving as an electronic device, which will be described later.

The liquid crystal panel 100 has a number of pixels (not shown) arranged in a matrix in the X and Y directions in the display area. The liquid crystal panel 100 is of an active drive type. For ease of explanation, the following description will use the mutually orthogonal X-axis, Y-axis, and Z-axis as appropriate. The direction along the X-axis will be referred to as the X-direction. Similarly, the direction along the Y-axis will be referred to as the Y-direction, and the direction along the Z-axis will be referred to as the Z-direction. In the following description, a view in the Z direction will be referred to as a "planar view," and a view from a direction perpendicular to a cross section including the Z-axis will be referred to as a "cross-sectional view."

Although not shown, each pixel is provided with a pixel electrode, a switching element, a counter electrode, a storage capacitor, and the like. The switching element controls the switching of the pixel electrode. The counter electrode faces the pixel electrode via the liquid crystal layer. The pixel electrode, the switching element, and the storage capacitor are provided on the element substrate 10. The switching element is, for example, a thin film transistor (TFT). The counter electrode is provided on the counter substrate 20 across at least the display area so as to face the multiple pixel electrodes. The pixel electrode and the counter electrode are formed using a transparent conductive film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide).

A terminal section 40 is disposed on the protruding portion 12 of the element substrate 10. The terminal section 40 is a portion where a panel terminal 50 (see FIG. 3) serving as a terminal of the liquid crystal panel 100 and an external terminal 60 (see FIG. 3) of the wiring substrate 110 are electrically connected. The wiring substrate 110 is, for example, a flexible substrate such as an FPC (Flexible Printed Circuit). Although not shown, a driving IC is mounted on the wiring substrate 110. The driving IC does not have to be mounted on the wiring substrate 110.

As shown in Figs. 1 and 2, a first dustproof substrate 31 is disposed on the element substrate 10 side of the liquid crystal panel 100. A second dustproof substrate 32 is disposed on the opposing substrate 20 side of the liquid crystal panel 101.

As shown in FIG. 3, a terminal group having a plurality of terminal sections 40 is provided on the protruding portion 12 of the element substrate 10. The terminal section 40 is configured to include a panel terminal 50 formed on the liquid crystal panel 100, an external terminal 60 formed on the wiring substrate 110, and a particle-aligned anisotropic conductive film (ACF) 70 for electrically connecting the panel terminal 50 and the wiring substrate 110. In addition, alignment marks 11 for aligning the panel terminal 50 and the external terminal 60 are arranged on both sides of the terminal group having the plurality of terminal sections 40.

As shown in FIG. 4, multiple panel terminals 50 are arranged on the protruding portion 12 of the element substrate 10 along a first direction d1 (X direction) along one side 10a of the element substrate 10. The long sides 50L of the multiple panel terminals 50 are arranged at an angle θa with respect to a third direction d3 (Y direction) along the end side 10b of the element substrate 10. Specifically, the panel terminals 50 have long sides 50L along a second direction d2 that intersects obliquely with the first direction d1, and short sides 50S along a fourth direction d4 that is perpendicular to the second direction d2.

5, the external terminal 60 of the wiring board 110 is a portion of the wiring 61 made of patterned copper foil where the insulating film covering the wiring 61 at the tip side (end side 60b side) from the bent portion 60a has been removed. The external terminal 60 is inclined at an angle θa with respect to the end side 60c of the wiring board 110 between the bent portion 60a and the end side 60b. When the wiring board 110 is attached to the protruding portion 12 of the element substrate 10, the external terminal 60 and the panel terminal 50 are attached in a state inclined at an angle θa with respect to the end side 10b along the third direction d3 (Y direction) of the element substrate 10 (see FIG. 3). The wiring 61 is not inclined except for the portion of the external terminal 60, and is arranged parallel to the extension direction (third direction d3) of the end side 60c of the wiring board 110. The bent portion 60a of the external terminal 60 is attached to the panel terminal 50 so that it is positioned on one side 10a of the element substrate 10 (see FIG. 3).

The bent portion 60a of each wiring 61 will be described. As shown in FIG. 5, if the line segment connecting the bent portion 60a of each wiring 61 is parallel to the end side 60b, and as shown in FIG. 7, if the line segment connecting the two bent points constituting the bent portion 60a of each wiring 61 is inclined counterclockwise with respect to the end side 60b, the width of the wiring 61 will be the region along the third direction d3 (Y direction) < the region along the second direction d2. On the other hand, if the line segment connecting the two bent points constituting the bent portion 60a of each wiring 61 is parallel to the end side 60b, the width of the wiring 61 will be the region along the third direction d3 (Y direction) > the region along the second direction d2. In any case, if the width of the wiring 61 is such that the area along the third direction d3 (Y direction) ≠ the area along the second direction d2, the line segment connecting the bent portions 60a of each wiring 61 will be parallel to the end edge 60b, and there is no need to unnecessarily lengthen the wiring board 110 or bend it.

By tilting the line segment connecting the bent portions 60a of each wiring 61 counterclockwise with respect to the end edge 60b, and tilting the line segment connecting the two bending points that make up the bent portion 60a of each wiring 61 counterclockwise with respect to the end edge 60b, the width of the wiring 61 can be made to be the area along the third direction d3 (Y direction) = the area along the second direction d2.

As shown in FIG. 6, in the particle-aligned anisotropic conductive film 70, the conductive particles 71 are arranged in a regular array in a predetermined array pattern in a plan view. Specifically, the conductive particles 71 are arranged in a matrix shape at equal intervals in a direction x1 parallel to the longitudinal direction and a direction y1 perpendicular to the longitudinal direction. When the particle-aligned anisotropic conductive film 70 is attached to the liquid crystal panel 100, it is attached to the protruding portion 12 of the liquid crystal panel 100 so that the array direction (x1, y1) of the conductive particles 71 is along a first direction d1 along one side 10a of the element substrate (see FIG. 4) and a third direction d3 perpendicular to the first direction d1.

In this embodiment, the conductive particles 71 are regularly arranged in a predetermined arrangement pattern, which means that the arrangement of a large number of conductive particles 71 on the panel terminal 50 has regularity. The arrangement of the conductive particles 71 may not be all regularly arranged due to manufacturing reasons of the particle-aligned anisotropic conductive film 70. Therefore, even on the panel terminal 50, some particles may irregularly deviate from the predetermined arrangement axis or the predetermined arrangement interval, but this does not mean that the particles are not regularly arranged. In addition, between the panel terminals 50, the conductive particles 71 may deviate from the predetermined arrangement axis or the predetermined arrangement interval after compression due to the fluidity of the binder that constitutes the particle-aligned anisotropic conductive film 70, but this does not mean that the particles are not regularly arranged.

Figure 7 is an enlarged plan view of the terminal portion 40 shown in Figure 3. Figure 16 is a cross-sectional view of the terminal portion 40 in Figure 7 taken along line segment B-B' parallel to the second direction d2, viewed from the fourth direction d4. Figure 17 is a cross-sectional view of the terminal portion 40 in Figure 7 taken along line segment C-C' parallel to the fourth direction d4, viewed from the second direction d2. The fourth direction d4 is parallel to the extension direction of the short side 50S of the panel terminal 50, or perpendicular to the extension direction (second direction) of the long side 50L of the panel terminal 50.

7, according to this embodiment, the panel terminal 50 is arranged in the protruding portion 12 so that the extension direction of the long side 50L is oblique to one side 10a (see FIG. 4) of the liquid crystal panel 100. In addition, the particle-aligned anisotropic conductive film 70 is arranged so that the arrangement direction (x1, y1) (see FIG. 6) of the conductive particles 71 is the first direction d1 and the third direction d3, respectively. As a result, the arrangement direction of the conductive particles 71 obliquely intersects with the extension direction (second direction d2) of the long side 50L of the panel terminal 50, so that the arrangement of the conductive particles 71 can be made dense when the panel terminal 50 is viewed from a direction perpendicular to the long side 50L or short side 50S of the panel terminal 50 (fourth direction d4 or second direction d2). Although it is difficult to freely change the arrangement direction of the conductive particles 71 in the particle-aligned anisotropic conductive film 70, the density of the arrangement of the conductive particles 71 can be adjusted by adjusting the angle θa, so that an optimal terminal configuration can be obtained.

In other words, as shown in FIG. 16, when the panel terminal 50 is viewed in a direction perpendicular to the long side 50L of the panel terminal 50 (the fourth direction), due to the large number of conductive particles 71 regularly arranged in the first direction d1 and the third direction d3, the conductive particles 71 are arranged without any gaps between the external terminal 60 of the wiring board 110 and the panel terminal 50 of the element substrate 10, and it appears as if there is a continuous conductor crossing between the external terminal 60 and the panel terminal 50.

Also, as shown in FIG. 17, due to the numerous conductive particles 71 regularly arranged in the first direction d1 and the third direction d3, when the panel terminal 50 is viewed in a direction perpendicular to the short side 50S of the panel terminal 50 (second direction), the conductive particles 71 are arranged without any gaps between the external terminal 60 of the wiring board 110 and the panel terminal 50 of the element substrate 10, making it appear as if there is a continuous conductor crossing between the external terminal 60 and the panel terminal 50.

In addition, in FIG. 7, the hatched conductive terminals 71a, 71b, and 71c indicate conductive particles 71 located between the panel terminal 50 and the external terminal 60 and electrically connected to both terminals. As shown in FIG. 7, the conductive particles 71 electrically connected to both terminals are composed of the n-th row of conductive particles 71a, the n+1-th row of conductive particles 71b, and the n+2-th row of conductive particles 71c. Therefore, compared to the case where the arrangement direction of the panel terminal 50 and the external terminal 60 is the same as the arrangement direction of the conductive particles 71, the number of rows to which the conductive particles 71 that contribute to the electrical connection between the panel terminal 50 and the external terminal 60 belong can be increased.

Therefore, when the external terminal 60 and the panel terminal 50 face each other, there is always a portion that is in contact with the conductive particles 71. This increases the reliability of the electrical connection between the panel terminal 50 and the external terminal 60.

In addition, since the particle-aligned anisotropic conductive film 70 does not need to be tilted with respect to the external shape of the liquid crystal panel 100 when it is attached, it is easy to ensure a clearance so that the particle-aligned anisotropic conductive film 70 does not interfere with the opposing substrate 20 when attaching the particle-aligned anisotropic conductive film 70 or when attaching the wiring substrate 110, and therefore the liquid crystal panel 100 does not become enlarged. In addition, since the particle-aligned anisotropic conductive film 70 does not need to be tilted, for example, it is possible to use the alignment mark 11 of the panel terminal 50 as the alignment mark of the particle-aligned anisotropic conductive film 70, thereby improving the space efficiency of the liquid crystal panel 100.

In addition, since the bent portion 60a of the external terminal 60 of the wiring board 110 is provided closer to one side 10a of the element board 10 than the panel terminal 50, even if there is misalignment due to the wiring board 110 stretching in the X direction due to the application of heat during mounting, it is possible to prevent the external terminal 60 from coming into unintended contact with the adjacent panel terminal 50, thereby suppressing a decrease in yield. Furthermore, since the inclination angle of the external terminal 60 is not changed on the end side of the wiring board 110, even if there is a similar misalignment during mounting, it is possible to prevent the external terminal 60 from coming into contact with the adjacent panel terminal 50.

As shown in FIG. 8, the projector 1000 as an electronic device of this embodiment includes a polarized lighting device 1100 arranged along the system optical axis L, two dichroic mirrors 1104 and 1105 as light separation elements, three reflecting mirrors 1106, 1107 and 1108, five relay lenses 1201, 1202, 1203, 1204 and 1205, three transmissive liquid crystal light valves 1210, 1220 and 1230 as light modulation means, a cross dichroic prism 1206 as a light combining element, and a projection lens 1207.

The polarized lighting device 1100 is roughly composed of a lamp unit 1101 as a light source consisting of a white light source such as an ultra-high pressure mercury lamp or a halogen lamp, an integrator lens 1102, and a polarization conversion element 1103.

Dichroic mirror 1104 reflects the red light (R) and transmits the green light (G) and blue light (B) of the polarized light beam emitted from polarized lighting device 1100. The other dichroic mirror 1105 reflects the green light (G) that has passed through dichroic mirror 1104 and transmits the blue light (B).

The red light (R) reflected by the dichroic mirror 1104 is reflected by the reflecting mirror 1106 and then enters the liquid crystal light valve 1210 via the relay lens 1205. The green light (G) reflected by the dichroic mirror 1105 enters the liquid crystal light valve 1220 via the relay lens 1204. The blue light (B) transmitted through the dichroic mirror 1105 enters the liquid crystal light valve 1230 via a light guide system consisting of three relay lenses 1201, 1202, and 1203 and two reflecting mirrors 1107 and 1108.

The liquid crystal light valves 1210, 1220, and 1230 are arranged to face the entrance surface of the cross dichroic prism 1206 for each color of light. The colored light incident on the liquid crystal light valves 1210, 1220, and 1230 is modulated based on the video information (video signal) and emitted toward the cross dichroic prism 1206.

This prism is made by bonding together four right-angle prisms, and on its inner surface a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape. These dielectric multilayer films combine the three color lights to combine light that represents a color image. The combined light is projected onto the screen 1300 by the projection lens 1207, which is a projection optical system, and the image is enlarged and displayed.

The liquid crystal light valve 1210 is an application of the above-mentioned liquid crystal device 500. The liquid crystal device 500 is arranged with a gap between a pair of polarizing elements arranged in a crossed Nicol configuration on the entrance side and exit side of the colored light. The other liquid crystal light valves 1220 and 1230 are similar.

In addition to the projector 1000, the liquid crystal device 500 can be used in a variety of electronic devices, including head-up displays (HUDs), head-mounted displays (HMDs), smartphones, EVFs (Electrical View Finders), mobile mini projectors, e-books, mobile phones, mobile computers, digital cameras, digital video cameras, displays, in-vehicle equipment, audio equipment, exposure equipment, and lighting equipment.

As described above, the liquid crystal device 500 of the first embodiment includes a liquid crystal panel 100 and a wiring substrate 110 electrically connected to a terminal portion 40 of the liquid crystal panel 100 by conductive particles 71 arranged in an aligned state in a planar view. The terminal portion 40 has a plurality of panel terminals 50 arranged along a first direction d1 along one side 10a of the liquid crystal panel 100. The panel terminals 50 have a long side 50L along a second direction d2 that intersects diagonally with the first direction d1 and a short side 50S along a fourth direction d4 that intersects with the second direction d2. The conductive particles 71 are arranged along a third direction d3 that intersects with the second direction d2.

With this configuration, the extension direction of the panel terminals 50 and the arrangement direction of the conductive particles 71 are different, so that when, for example, a particle-aligned anisotropic conductive film 70 is attached to the area where the terminal portion 40 of the liquid crystal panel 100 is arranged, and the liquid crystal panel 100 and the wiring board 110 are connected by pressure bonding, it is possible to prevent the number of conductive particles 71 sandwiched between the panel terminals 50 from being drastically reduced or the occurrence of variation between terminals. This makes it possible to prevent poor connection between the liquid crystal panel 100 and the wiring board 110.

In addition, while selecting a particle-aligned anisotropic conductive film 70 that matches the pitch of the panel terminals 50 has traditionally been an important issue, the options for particle-aligned anisotropic conductive films 70 have expanded, and the arrangement direction of the conductive particles 71 of the particle-aligned anisotropic conductive film 70 can be set arbitrarily depending on the inclination angle of the panel terminals 50. Since the arrangement density of the conductive particles 71 in the length and width directions of the panel terminals 50 can be effectively made smaller than the arrangement pitch of the conductive particles 71 on the particle-aligned anisotropic conductive film 70, electrical connectivity with the wiring board 110 is also improved. Furthermore, this configuration makes it possible to provide an electro-optical device and electronic device that can flexibly accommodate narrower terminal pitches.

In addition, since the projector 1000 is equipped with the liquid crystal device 500 described above, it is possible to provide a projector 1000 that can provide a stable display.

Second embodiment As shown in Fig. 9, a liquid crystal panel 101 of the second embodiment differs from the liquid crystal panel 100 of the first embodiment in that the angle of the long side of the panel terminal 50 in contact with the conductive particles 71 is different from the angle of the long side of the lower layer electrode 51 arranged in the lower layer therebelow. The other configurations are generally similar. Therefore, in the second embodiment, the parts that differ from the first embodiment will be described in detail, and the description of the other overlapping parts will be omitted as appropriate.

As shown in Figures 9 and 10, the terminal section 140 of the liquid crystal panel 101 of the second embodiment has a plurality of lower layer electrodes 51a to 51c. For example, the terminal section 140 has an insulating layer 14a, a lower layer electrode 51a which is part of the conductive layer, an interlayer insulating layer 14b, a lower layer electrode 51b which is part of the conductive layer, an interlayer insulating layer 14c, a lower layer electrode 51c which is part of the conductive layer, an interlayer insulating layer 14d, and a panel terminal 50, which are arranged in this order on the substrate 15. Here, the lower layer electrodes 51a to 51c are collectively referred to as the lower layer electrodes 51.

The panel terminal 50 and the lower electrode 51 are electrically connected through a relay electrode 52r arranged in the contact hole 52. The lower electrode 51b and the lower electrode 51c are also electrically connected through a relay electrode 53r arranged in the contact hole 53. Here, the insulating layer 14a is a gate insulating film of a thin film transistor formed on the element substrate 10. The lower electrode 51a is, for example, a gate electrode layer of a thin film transistor formed on the element substrate 10, and is also used for a gate electrode line arranged in the display area of the element substrate 10. The lower electrode 51b is, for example, a source electrode or drain electrode layer of a thin film transistor formed on the element substrate 10, and is used for wiring between thin film transistors and for a signal line arranged in the display area of the element substrate 10. The lower electrode 51c is, for example, used for a storage capacitance line arranged in the display area, and is also used as a wiring to assist the lower electrode 51b. The panel terminal 50 is, for example, a pixel electrode layer formed on the element substrate 10. Although the contact structure connecting the lower layer electrodes 51a and 51b is not shown, they are connected by a contact structure in the peripheral circuit formed on the element substrate 10. Note that the interlayer insulating layer 14b includes a capacitance layer that constitutes a storage capacitance provided in the pixels of the display area, but is abbreviated as a single insulating layer for ease of explanation.

As in the first embodiment, the panel terminal 50 is arranged at an angle θa with respect to the edge 10b of the element substrate 10 along the Y direction (see FIG. 3). The lower layer electrode 51 is arranged without inclination with respect to the edge 10b of the element substrate 10 along the Y direction. Specifically, the long side of the panel terminal 50 is arranged along the second direction d2, and the long sides of the lower layer electrodes 51a to 51c are arranged along the Y direction (third direction d3) that intersects at a right angle with the first direction d1. Note that the lower layer electrodes 51 may be arranged so that all the lower layer electrodes 51a to 51 are not inclined, or some of them may be arranged at an angle θa like the panel terminal 50.

The multiple contact holes 52 are arranged in a plan view in the area where the panel terminal 50 and the lower layer electrode 51 overlap, and along the long side of the lower layer electrode 51. This results in the contact holes 52 being unevenly distributed within the area of the lower layer electrode 51.

If the entire terminal section 140, which is made up of the panel terminal 50, lower layer electrode 51, contact hole 52, etc., is simply tilted, a problem occurs in that the shape that defines the terminal section 140 does not fit on the working grid used to create the photomask. In that case, the photomask will have an unintended shape and dimensions, which will interfere with the fine processing of the contact holes 52, etc., causing variations in contact resistance, for example.

In addition, when the particle-aligned anisotropic conductive film 70 is discontinued, the inclination angle of the terminal portion 140 may be changed as a result of changing the particle-aligned anisotropic conductive film 70 used. Specifically, the arrangement pitch of the conductive particles 71 in the replacement product is different, so that it is desired to change the effective arrangement density of the conductive particles 71 in the length direction and width direction of the panel terminal 50. In that case, changing the entire structure of the terminal portion 140 also causes cost problems. However, by configuring the terminal portion 140 as described above, it is possible to make the panel terminal 50 other than the panel terminal 50 in an on-grid shape, except for the panel terminal 50 that contacts the conductive particles 71. Furthermore, since the contact holes 52 are unevenly arranged within the region of the lower electrode 51, even if the inclination angle is changed from, for example, θa to another angle, the contact holes 52 are not exposed, and no process problems are caused, so only the photomask of the panel terminal 50 needs to be changed.

As described above, the terminal portion 140 of the liquid crystal panel 101 of the second embodiment has a panel terminal 50 that contacts the conductive particles 71, and lower layer electrodes 51a to 51c that are arranged below the panel terminal 50 and overlap the panel terminal 50 in a planar view, with the long side of the panel terminal 50 arranged along the second direction d2 and the long sides of the lower layer electrodes 51a to 51c arranged along the third direction d3 that intersects at a right angle to the first direction d1.

With this configuration, since the panel terminals 50 are inclined, it is possible to prevent the number of conductive particles 71 sandwiched between the panel terminals 50 from being drastically reduced or to prevent variations from occurring between terminals. In addition, it becomes easier to control the fine processing of the contact holes 52, etc., and it is possible to reduce variations in contact resistance. The inclination angle of the panel terminals 50 can also be changed at low cost.

The configuration is not limited to the first and second embodiments described above, and may be as follows. Figures 11 to 15 are plan views showing the configurations of terminal portions 141, 142, 143, 144, and 145 of modified examples 1 to 5.

As shown in FIG. 11, in the terminal portion 141 of the first modified example, the shape of the panel terminal 150 is a parallelogram. Specifically, if the angle of the panel terminal 50 is simply rotated by θa, as in the terminal portion 140 of the second embodiment, the vertices of the rectangle of the panel terminal 50 may not be on the working grid when creating the photomask. In that case, the photomask may be created with an unintended size, resulting in a situation in which the dimensions of the panel terminal 50 are slightly different. However, by using such a shape, the panel terminal 150 can be made into an on-grid figure while being tilted, so the area of the panel terminal 150 can be formed stably.

As such, it is preferable that the shape of the panel terminal 150 is a parallelogram. With this configuration, since the shape of the panel terminal 150 is a parallelogram, the extension direction of the panel terminal 150 can be tilted with respect to one side 10a of the liquid crystal panel 100, and the panel terminal 150 can be formed reliably.

As shown in FIG. 12, the terminal portion 142 of the second modified example is arranged with the lower layer electrode 151 tilted to match the tilt of the panel terminal 150. For example, in the first modified example of FIG. 11, the length of the long side of the panel terminal 150 is, for example, 500 μm, and the tilt angle θa is 4°. The arrangement pitch in the X direction of the structure consisting of the lower layer electrode 51 is 50 μm, the width is 35 μm, and the space is 15 μm. In this case, the dimension L1 is 250 μm × tan 4° = 18 μm.

In this case, the dimension L1 becomes larger than the space of 15 μm between the structure made of the lower layer electrodes 51, so the panel terminal 150 overlaps the lower layer electrode 51 of the adjacent terminal portion 141 in a plan view. Pressure is applied during mounting, and depending on the thickness of the insulating layer, this may result in a short circuit between the lower layer electrode 51c and the panel terminal 150, for example. Therefore, as shown in Variation 2 of FIG. 12, at least a part or all of the lower layer electrodes 151 are formed into a parallelogram like the panel terminal 150. With this configuration, it is possible to avoid overlap between the panel terminal 150 and the lower layer electrode 151 of the adjacent terminal portion 142 in adjacent terminal portions 142.

In this way, it is preferable that the panel terminal 150 does not overlap the lower layer electrode 151 of the adjacent terminal portion 142 in a plan view. With this configuration, since the panel terminal 150 does not overlap the lower layer electrode 151 of the adjacent terminal portion 142, it is possible to prevent a short circuit between the panel terminal 150 and the lower layer electrode 151 of the adjacent terminal portion 142 due to the stress of the compression when the liquid crystal panel 100 and the wiring board 110 are compressed together.

As shown in FIG. 13, in the terminal portion 143 of the third modified example, the contact holes 152 are arranged over the entire surface of the panel terminal 150 while gradually moving the X coordinate along the shape of the panel terminal 150. Specifically, the contact holes 152 are arranged roughly along one side of the parallelogram of the panel terminal 150.

In this case, the drawing can be performed by setting a virtual line along which the contact holes 152 are to be placed, mechanically calculating the X coordinate closest to this virtual line for each placement pitch of the contact holes 152 in the Y direction by rounding it to the value of the working grid for creating the photomask, and writing and executing a program to place the basic shape of the contact holes 152. Functions for writing and executing any drawing program are implemented in commercially available drawing software for creating photomasks.

In this way, it is preferable that a plurality of contact holes 152 are arranged between the panel terminal 150 and the lower layer electrode 151, and that the plurality of contact holes 152 are arranged along the second direction.

This configuration makes it possible to prevent the lower layer electrode 51 from becoming an off-grid shape. In addition, since the contact holes 152 are arranged over almost the entire surface of the panel terminal 150 (lower layer electrode 151), the number of contact holes 152 can be increased, thereby improving the reliability of the electrical connection between the panel terminal 150 and the lower layer electrode 151.

Alternatively, the contact holes 152 are preferably arranged randomly within a range of a predetermined pitch A or more and B or less. Pitch A is a spacing rule determined by the processing performance of the contact holes 152, and is, for example, 1 μm. Pitch B is determined by the size and number of contact holes to be placed, and is, for example, 10 μm. In this way, the spacing rule is observed and at least one contact hole is placed within a 10 μm range.

This configuration makes it possible to increase the number of contact holes 152 so that they fit within the parallelogram, reducing electrical resistance. This allows for stable signal and power supply.

In addition, when managing the mounting process of the wiring board 110, it may be necessary to check the arrangement direction of the conductive particles 71. If the element board 10 is a transparent board such as quartz, the conductive particles 71 can be observed from the back side of the element board 10, but since a silicon board or the like is opaque, they are observed from the film formation surface, i.e., the wiring board 110 side. In this case, if the contact holes 152 are randomly arranged, it becomes easier to distinguish them from the contact holes 152 when observing the arrangement of the conductive particles 71 on the panel terminals 150 with a microscope or the like. For example, if a structure with three evenly spaced structures is found, it becomes easier to determine that this is the arrangement axis of the conductive particles 71.

As shown in FIG. 14, the terminal portion 144 of the fourth modification, like the terminal portion 141 of the first modification shown in FIG. 11, has a shape in which the portion of the lower layer electrode 51 that protrudes from the shape of the panel terminal 150 is removed to form a lower layer electrode 251. Specifically, at least a part or all of the portion adjacent to the adjacent terminal portion 141 is cut out, and in FIG. 14, a deformed hexagon is formed. With this configuration, overlap between the panel terminal 150 and the lower layer electrode 251 of the adjacent terminal portion 144 can be avoided in adjacent terminal portions 144, and therefore short circuit failure between the panel terminal 150 and the lower layer electrode 251 can be avoided.

15, the terminal portion 145 of the fifth modification is formed with the lower layer electrode 351 having a width that matches the size of the contact hole 252. Specifically, the contact holes 252 are arranged in a line parallel to the Y direction of the element substrate 10. For example, among the signals supplied from the terminal portion 145, there are logic signals such as so-called clock signals, which are typically input to a buffer circuit of the internal circuit of the display panel, so that there is no problem even if the contact resistance becomes relatively large. In that case, the width of some or all of the lower layer electrodes 351 other than the panel terminal 150 may be configured to be smaller than that of the panel terminal 150. Even with this configuration, overlapping with the lower layer electrodes 351 of adjacent terminal portions 145 can be avoided, so that short-circuit failure between the panel terminal 150 and the lower layer electrodes 351 of the adjacent terminal portions 145 can be avoided. The contact holes 252 may be arranged in a line in accordance with the inclination of the panel terminal 150, and the lower layer electrodes 351 may also be formed in accordance with the inclination of the contact holes 252. The contact holes 252 may be in multiple rows.

In the embodiment, when the particle-aligned anisotropic conductive film 70 is attached to the liquid crystal panel 100, the conductive particles 71 are arranged in a matrix along the direction of one side 10a of the element substrate (first direction d1) and the direction perpendicular to that (third direction d3), but this is not limited to this. They may be inclined with respect to the direction of one side 10a of the element substrate and the direction perpendicular to that. Alternatively, instead of a matrix arrangement, the particle-aligned anisotropic conductive film may have the conductive particles 71 aligned at the center of a regular hexagon and the vertices of each side. In either case, the configuration of the present application allows the relationship between the arrangement direction of the conductive particles 71 and the inclination angle of the panel terminals 50, etc. to be set arbitrarily, so that an optimal design can be adopted.

In the embodiment, the wiring substrate 110 is mounted on the liquid crystal panel 100 using the particle-aligned anisotropic conductive film 70, but this is not limited to the above. For example, a COG (Chip On Glass) configuration may be used in which a driving IC is mounted on the element substrate 10 of the liquid crystal panel 100 using the particle-aligned anisotropic conductive film 70. A COF (Chip On Film) configuration may also be used.

Furthermore, the electro-optical device is not limited to the liquid crystal device 500 described above, but may be applied to, for example, an organic EL device, a head-up display (HUD), an electronic paper display (EPD), etc.

10...element substrate, 10a...one side, 11...alignment mark, 14a...insulating layer, 14b, 14c, 14d...interlayer insulating layer, 12...projection, 15...base material, 20...opposite substrate, 31...first dust-proof substrate, 32...second dust-proof substrate, 40...terminal portion, 50...panel terminal as terminal, 51, 51a, 51b, 51c...lower layer electrode, 60...external terminal, 60a...bent portion, 70...anisotropic conductive film, 71...conductive particles, 100, 101...liquid crystal panel as electro-optical panel, 110...wiring substrate, 140, 141, 142, 143, 144, 145...terminal portion, 150...panel terminal, 15 1,251,351...Lower layer electrode, 500...Liquid crystal device as electro-optical device, 1000...Projector as electronic device, 1100...Polarized lighting device, 1101...Lamp unit, 1102...Integrator lens, 1103...Polarization conversion element, 1104, 1105...Dichroic mirror, 1106, 1107, 1108...Reflecting mirror, 1201, 1202, 1203, 1204, 1205...Relay lens, 1206...Cross dichroic prism, 1207...Projection lens, 1210, 1220, 1230...Liquid crystal light valve, 1300...Screen.

Claims (6)

An electro-optical panel;
a wiring board electrically connected to a terminal portion of the electro-optical panel by conductive particles arranged in a state aligned in a plan view;
An electro-optical device comprising:
the terminal portion includes a plurality of terminals arranged in a first direction along one side of the electro-optical panel,
the terminal has a long side along a second direction that obliquely intersects the first direction, and a short side along a direction that intersects the second direction,
The conductive particles are arranged along a third direction intersecting the second direction ,
The terminal portion includes the terminal that contacts the conductive particles and a flat terminal disposed below the terminal.
a lower layer electrode overlapping the terminal in plan view,
The terminals are arranged such that the long sides of the terminals are aligned along the second direction,
the third direction intersects with the first direction at a right angle,
The electro-optical device , wherein the lower layer electrode is disposed such that a longer side of the lower layer electrode is aligned along the third direction. 2. The electro-optical device according to claim 1 ,
The electro-optical device is characterized in that the terminals do not overlap with lower electrodes of adjacent terminal portions in a plan view. 3. The electro-optical device according to claim 1,
The electro-optical device, wherein the terminal has a shape of a parallelogram. 4. The electro-optical device according to claim 1 ,
a plurality of contact holes disposed between the terminal and the lower layer electrode;
The electro-optical device, wherein the plurality of contact holes are arranged along the second direction. 5. The electro-optical device according to claim 4 ,
The electro-optical device is characterized in that the contact holes are randomly arranged at a predetermined pitch in the range of A to B. 6. An electronic device comprising the electro-optical device according to claim 1 .

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